AbstractThe environmentally friendly and low‐priced CaYAlO4:Tb3+ nanophosphors are combined with good optically transparent materials for the application in 3D printing. For ultraviolet (UV) light‐emitting diode excitation, CaYAlO4:Tb0.07Cey and CaYAlO4:Ce0.05Tbx nanophosphors are prepared by a sol–gel route and systematically studied for optimal excitation at 380 nm to give strong green emission to which human and aquatic animals eyes are generally sensitive. This is benefited from the dipole and spin allowed transition of Ce3+ and the 92.5% efficient energy transfer from Ce3+ to Tb3+ in this host. Polydimethylsiloxane, with 92% transmittance in the visible spectral region, is a valid choice to make the shaped artwork by a templating method, combined with the nanoparticles to give a uniform distribution, as determined by X‐ray microcomputed tomography. Polylactic acid is also employed to create a frog artwork by the fused deposition modeling method. The final 3D‐printed colorful artwork is displayed herein together with that produced by the templating method under different light source excitation to suggest a novel expression of aesthetic concepts and a potential application in the future marine environment such as a lamp to attract aquatic animals or a buoy to guide ships.